The observed increase in the average temperature of the Earth's atmosphere and oceans in recent decades and its projected continuation into the future.

The prevailing scientific opinion on climate change is that "most of the warming observed over the last 50 years is attributable to human activities.

The main cause of the human-induced component of warming is the increased atmospheric concentration of greenhouse gases (GHGs) such as carbon dioxide (CO2). This leads to warming of the surface and lower atmosphere by increasing the greenhouse effect.

The current literature estimates sensitivity in the range 1.5-4.5°C (2.7-8.1°F). Models referenced by the Intergovernmental Panel on Climate Change (IPCC) predict that global temperatures may increase by between 1.4 and 5.8°C (2.5 to 10.5°F) between 1990 and 2100. The uncertainty in this range results from both the difficulty of predicting the volume of future greenhouse gas emissions and uncertainty about climate sensitivity.

An increase in global temperatures can in turn cause other changes, including a rising sea level and changes in the amount and pattern of precipitation. These changes may increase the frequency and intensity of extreme weather events, such as floods, droughts, heat waves, hurricanes, and tornados. Other consequences include higher or lower agricultural yields, glacier retreat, reduced summer streamflows, species extinctions and increases in the ranges of disease vectors. Warming is expected to affect the number and magnitude of these events; however, it is difficult to connect particular events to global warming. Although most studies focus on the period up to 2100, warming (and sea level rise due to thermal expansion) is expected to continue past then, since CO2 has a long average atmospheric lifetime.

Continuation...

Continuation...

While many agree with these basic statements much is argued about the science of global warming. Many argue that there are known broader weather cycles prior to these past 50 years and some believe these cycles have played out in between the greater weather “ages” many times.

Others while believing that human activity has had an extreme impact on nature argue the methodology or modeling that projects future consequences based on these past 50 years.

Beyond the science it is assumed that anything the individual can do to lessen their personal carbon footprint can only go to reducing the human contribution to global warming.

Tim,
I would just like to point out that as editor of On Line Opinion it is my job to decide what makes the grade and what doesn't when it comes to publishing articles in the journal. Very occasionally I will confer with Graham Young; usually when I feel there may be legal implications for us. I don't belong to any political party and I judge what is going to be published by a number of factors. One of my most important tasks is to make sure, as far as is humanly possible, I give a balanced coverage to the really hot topics: climate change; abortion; education, politics; Middle East and so on. Of course there are many other considerations when deciding what to publish but I like to think here at OLO we can offer a huge range of opinions and a broad range of topics.
Susan Prior - editor

Regarding point 6.

Variables that affect land sea encroachment:

1. Tides - we all know there are low and high tides but that isn't the whole story. The gravity of the moon, the sun and to a smaller extent the other heavenly bodies are relevant. The distance of the earth to each of those can vary and any point is also subject to the earth's tilt. Also localised drainage dynamics come into play e.g. the capacity of an inlet to drain/fill (for open ocean conditions not much of a factor). A tide height/probability chart would given you a classic bell curve i.e. LOTS of different tide heights with extremes not very likely but they will happen from time to time.

2. Waves - the tide determines the flat water sea level, the wave adds additional encroachment. Wave heights vary alot, anything from a few centimetres to a few metres when you've had a fierce storm nearby. Again we have the bell curve to show the probability of a given wave height occurring. LOTS of different wave heights possible, LOTS of different wave encroachments possible.

3. Erosion - coasts are often made of soft sand, water moves sand, tides/waves move sand, water makes its way further in. Some areas have it, some don't, some might have the opposite (land run-off??).

4. Ocean volume - seems to be one variable at the moment affecting this, that is the ice/water ratio. Reports have it increasing at "a few" mm per year since 1900 (http://en.wikipedia.org/wiki/Image:Recent_Sea_Level_Rise.png).

In light of the above I make the following statement:

TBC...

...

Any person who currently has issues with sea encroachment in the current globally warmed high sea level environment was ALREADY STUFFED before global warming. Each time the extremes of the variables 1-2 came together, and/or the effect of 3 took hold, you were already finding yourself ankle deep in water. The only statement I expect to hear from such people now would go something like this - "It used to be that we only had water around our ankles 4 times a year, but this year it happened 5 times. Furthermore I noticed the water once hit my shin mole and that has never happened before. This is too much, we're moving to Kiwi land!".

I know the addition of variable 4 to the extreme occurence will add a bit more, but it is just a bit more, and it is only a very rare occurrence, I can't see that making people move countries who wouldn't have otherwise. Many people live in high flood risk areas nowhere near the sea and still manage to pull through after each occurrence. Also tide and wave extremes may not have changed over the years but erosion has alway been around and has posed problems for those living "on the edge" (I can't picture the local land management office on these remote islands amounting to much). One needs to ask why it is that where people have always had issues with high sea levels (http://www.freewillblog.com/index.php/weblog/comments/7034/) they are now being surrounded by camera crews and shoved in our faces as "environmental refugees".

Of course, there may well have been some migrants to New Zealand that actually did calim they were victims of sea level rise. But there is nothing that pricks the ears of a prospective migrant like a good story that will get their foot in the door. Some of the stories they give would deserve a Booker Prize if they were published.

But those stupid enough to use the number of reported "political" refugees as evidence of the incidence of persecution would be just as dumb as those who accept so-called climate refugees as evidence of sea level rising.